Medication error, a common type of medical error, carries a tremendous social burden. An estimated 770,000 Americans each year experience adverse drug events that result in injury or death at a total cost of $2 billion. These statistics have made the reduction of medication errors a national priority. Because of the number of medications prescribed in the outpatient setting and because most data on medication errors come from the inpatient setting, the Institute of Medicine has called for more research on medication errors in the outpatient setting. This K08 application outlines a five-year plan to support a candidate who is already contributing to clinical research on outpatient medication safety. The candidate is a clinical pharmacist with 10 years of working experience and specialty training in primary care and strong support from her academic department. In addition, she has substantial experience teaching pharmacotherapy and conducting practice- based research on medication safety. The career development plan provides a sequence of carefully selected training and mentoring experiences, including doctoral-level health services researchcoursework, mentored research leading to collaborative studies and publications, and professional networking, that will catapult her to the next level of research achievement. Her proposed research program, Safe Use of Medications in Primary Care Practices, has three specific aims: 1) to identify exemplary methods and exemplars for medication reconciliation (i.e., capturing and resolving discrepancies in the medications actually being taken and those recorded in patients' medical records); 2) to evaluate the feasibility of exemplary methods for medication reconciliation on primary care patients taking multiple medications; and 3) to disseminate study results and to extend the scope of this work in proposals to conduct outcomes trials.